【Q&A Question 061】2016.06.20
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【Q&A Question 061】June 20, 2016: How is the catalyst temperature controlled during the catalyst presulfidization process? The answer key will be available after responding; scoring is based on answering the key points. (1) Control the amount of vulcanizing agent injected. (2) Cold hydrogen control during over-temperature.
(1) Control the amount of vulcanizing agent injected. (2) Cold hydrogen control during over-temperature.
Control the reactor inlet temperature, control the sulfur injection amount
The most important factor is probably the amount of cold hydrogen injected, right?
Catalyst presulfurization can be divided into wet sulfurization and dry sulfurization. Wet sulfurization involves presulfurization in a liquid or semi-liquid state using distillate oil containing sulfides in the presence of hydrogen； Wet vulcanization is further divided into two types: in one type, the sulfur required for the catalyst vulcanization process is supplied from externally added sulfides, while in the other type, pre-vulcanization is carried out using the sulfur present in the sulfurized oil itself. Dry vulcanization involves vulcanization directly in the presence of hydrogen, either by using H2S at a certain concentration or by injecting organic sulfides into the circulating oxygen.
Heating furnace, reboiler, or heat exchanger
Control the heating rate and vulcanization temperature at each stage
By controlling the heating rate and the vulcanization temperature at each stage, it should be noted that the vulcanization reaction is an exothermic reaction; if the heating rate is too high or too much vulcanizing agent is added, the reaction will become intense, leading to overheating of the bed. Therefore, after introducing the vulcanizing agent, close attention must be paid to the temperature rise in the bed; the rate of temperature increase should be slow. Once the temperature rise exceeds 25°C, the amount of vulcanizing agent injected should be reduced or the temperature at the reactor inlet should be lowered. If the circulation of hot oil in the fractionation section affects the temperature rise requirements for pre-vulcanization, make appropriate adjustments to meet those requirements.
Adjust the injection volume of the vulcanizer and the amount of recycled hydrogen